Support continuation token in paging

[msyyc]

Auto PR for microsoft/typespec#6242

[tadelesh]

some concern for the generated code.

[Copilot]

PR Overview

This PR implements a safer data extraction mechanism for paging operations by replacing direct dictionary key access with a .get call that provides an empty list as a fallback. It also updates the naming of the continuation token property in the paging metadata.

• Safely handles missing keys in JSON responses by using .get.
• Renames "continuationTokenName" to "nextLinkName" in one of the formatter modules.

Reviewed Changes

File	Description
packages/autorest.python/test/azure/version-tolerant/Expected/AcceptanceTests/PagingVersionTolerant/pagingversiontolerant/operations/_operations.py	Updated extraction of paging elements using .get with default empty list.
packages/autorest.python/test/azure/version-tolerant/Expected/AcceptanceTests/CustomPollerPagerVersionTolerant/custompollerpagerversiontolerant/(aio/)operations/_operations.py	Replaced dictionary indexing with .get for both "value" and "values" keys in async and sync operations.
packages/autorest.python/test/azure/version-tolerant/Expected/AcceptanceTests/PagingVersionTolerant/pagingversiontolerant/aio/operations/_operations.py	Same safe-get updates for paging data extraction.
packages/autorest.python/test/azure/version-tolerant/Expected/AcceptanceTests/CustomUrlPagingVersionTolerant/custombaseurlpagingversiontolerant/(aio/)operations/_operations.py	Updates similar safe extraction for paging with custom base URLs.
packages/autorest.python/test/azure/version-tolerant/Expected/AcceptanceTests/LroPagingVersionTolerant/(aio/)operations/_operations.py	Consistent changes to safely extract paging data in long-running operations.
packages/autorest.python/test/dpg/version-tolerant/Expected/AcceptanceTests/DPGCustomization…/_operations/_operations.py	Similar changes applied to paging extraction and continuation token handling.
packages/autorest.python/autorest/m4reformatter/init.py	Changes the paging metadata property name from "continuationTokenName" to "nextLinkName".
packages/autorest.python/test/azure/version-tolerant/Expected/AcceptanceTests/StorageManagementClientVersionTolerant/(aio/)operations/_operations.py	Updated dictionary access for paging elements in the Storage management client.

Copilot reviewed 40 out of 40 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

packages/autorest.python/autorest/m4reformatter/init.py:553

• The property name change from 'continuationTokenName' to 'nextLinkName' could affect downstream consumers. Please ensure that all corresponding references and documentation are updated accordingly.

operation["continuationTokenName"] = yaml_data["extensions"]["x-ms-pageable"].get("nextLinkName")